1. Field of the Invention
The present invention relates to a solid state imaging device, a method of driving a solid state imaging device and an image pickup apparatus.
2. Description of the Related Art
A solid state imaging device is broadly divided into a charge transfer solid state imaging device typified by a CCD (Charge Coupled Device) image sensor, and an X-Y addressing solid state imaging device typified by a MOS (Metal Oxide Semiconductor) image sensor. In recent years, the latter solid state imaging device, for example the MOS image sensor is mounted particularly for use in a low power consumption camera module for mobile appliances such as a cellular mobile phone and a high speed electronic still camera.
For example, in an electronic still camera which is demanded for high resolution, since a still picture taken by clicking a shutter is demanded for high definition, a solid state imaging device having a larger number of pixels is to be used. However, in the electronic still camera, moving images are shown on an electronic viewfinder and a small screen monitor to allow confirming a subject. Therefore, in the stage to confirm the subject, picture signals of relatively low resolution should be read out at high speed.
In the past, in order to read the picture signals of relatively low resolution at high speed, a pixel is formed to have a color filter having a predetermined color coding, a unit is made of a pixel block formed of a plurality of pixels adjacent to each other in the row wise direction (the direction along rows) and the column wise direction (the direction along columns), and information about pixels having a filter in the same color in the unit pixel block is added/averaged to read it as pixel information for a single pixel in simulation (for example, see Patent Reference 1: JP-A-2004-266369).